Internal combustion engines include camshafts that open and close valves regulating the combustion of fuel and air within combustion chambers of the engines. The opening and closing of the valves are carefully timed relative to a variety of events, such as the injection and combustion of fuel into the combustion chamber and the location of the piston relative to top-dead center (TDC). Camshaft(s) are driven by the rotation of the crankshaft via a drive member connecting these elements, such as a belt or chain. In the past, a fixed relationship existed between the rotation of the crankshaft and the rotation of the camshaft. Increasingly, internal combustion engines now use camshaft phasers that vary the phase of camshaft rotation relative to crankshaft rotation.
A variety of different camshaft phaser designs exist. Some camshaft phasers rely on hydraulic fluid to adjust the angular position of the camshaft relative to the crankshaft while others are actuated by electric motors that advance or retard the opening/closing of valves relative to crankshaft rotation. Camshaft phasers that are actuated by electric motors can use a plurality of gears to vary the angular position of a camshaft relative to a crankshaft. Vehicle designers work to create vehicle engines that consume less space while producing the same, if not more, horsepower. Designing vehicle engines having smaller physical dimensions can be furthered by reducing the size of engine components, such as camshaft phasers.